In the most general sense, this project has been concerned with the investigation of the variables which determine the degree to which stimuli come to influence the behaviors with which they are associated. For the most part, stimulus control has been operationally defined either as stimulus generalization slope or as discriminative performance, and research has involved experimental manipulations postulated to influence these measures of performance. It is expected that research will continue along many of the lines previously explored, although there will be some changes of emphasis. Up to the present time, the bulk of the work attempting to validate the Principal Investigator's concept of General Attention has employed the measure of generalization slope. Further research will extend the application of that concept to the facilitated acquisition of new discriminations. The role of the nature of the response requirement will be explored, as well as the transfer of an attentional set across motivation-reward systems. The assumption in the general attention position that animals can learn generally about the significance of stimuli is consistent with another cognitive interpretation, i.e., that Ss can learn about the significance of their behavior, i.e., about the contingencies which exist between their behavior and important environmental events. We have used autoshaping to demonstrate effects on acquisition of prior experience with instrumental contingencies. Further work will explore the role of amount and type of prior experience in autoshape acquisition, as well as investigating more generally the parameters which affect performance in the autoshape paradigm. An earlier line of research was concerned with the investigation of illusions involving sensory-tonic interaction and visual field dependency in pigeons, as reflected in a dislocation of the peak of generalization gradients. We have used a similar measure with human subjects to reveal effects of changes in adaptation level during the course of generalization testing. Future work will explore the application of the concept of adaptation level to generalization and discrimination learning in animals. Other proposed lines of research involve studies of memory in animals, successive discrimination reversals, and applications of the concept of preparedness of stimulus-response associations.